Method of making metal slugs.



No. 801,338. PATENTED OOT.10, 1905.

M. REID. METHOD OF MAKING METAL SLUGS.

APPLICATION FILED NOV. 28, 1904.

TINITED STATES PATENT orrrcn.

MARCELLUS REID, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO AMERICAN BALL COMPANY, OF PROVIDENCE, RHODE ISLAND, A CORPORATION OF RHODE ISLAND.

METHOD OF MAKING METAL SLUGS- Specification of Letters Patent.

Patented Oct. 10, 1905.

Application filed November 28,1904. Serial No. 234,490.

To all whom it warty concern.-

Be it known that I, MARonLLUs REID, of Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Methods of Making Metal Slugs, of which the following is a specification.

This invention relates to the manufacture of metal slugs or ball-blanks of approximately spherical form adapted to be converted into practically perfect balls by a suitable grinding operation.

The invention has for its object to enable slugs of this character to be economically produced, the slugs having such accuracy of form as to reduce to the minimum the expense and waste material involved in the grinding operation.

The invention consists in the improved method which I will now proceed to describe and claim.

Of the accompanying drawings, Figure 1 represents a plan view of a pair of cutters suitable for use in carrying my invention into effect. Figs. 2 to 8, inclusive, represent various stages of the operation of making a slug in accordance with my invention. Fig. 9 represents a perspective view of one of the completed slugs.

The same reference characters indicate the same parts in all the figures.

In the drawings, 20 20 represent a pair of rotary cutters, which are preferably discoidal plates arranged edge to edge in the same plane and each having a V-shaped cutting edge 21. Each of said edges preferably extends only partly around the periphery of the plate or disk on which it is formed and each has a minimum projection from the said periphery at its forward end 22, Fig. 1, the projection gradually increasing to make a portion of the cutting edge eccentric to the axis of the cutter, the eccentricity terminating between the forward end 22 and the rear end 23 of the cutting edge, so that the rear portion of the cutting edge is concentric with the axis of the cutter. This formation enables the eccentric portions of the cutters to cooperate in severing from a rod 24 a slug 25, having tapered or approximately hemispherical ends, as indicated by Figs. 3 and 4, the concentric portions of the cutters supporting the rod and preventing it from dropping between the cutters while the severed slug is being removed and presented to a pair of pressing-dies. The interruption of the continuity of the cutting edges enables the rod to drop between the cutters after the rear ends of the cutting edges have passed out of contactwith the rod, all as hereinafter described. The cutters may be driven by any suitable means in the direction indicated by the arrows in Fig. l.

52 and 53 represent blank-pressing dies adjacent to the cutters, each die having a hemispherical cavity. The upper die 52 may be fixed and the lower die 53 moved alternately toward and from the upper die.

59 59 represent jaws provided for carrying each blank from the cutters to a point between the dies when the lower die is depressed and holding the blank until the lower die rises sufficiently to engage the ends of the blank with the die-cavities.

It will be seen that the cutters in severing a slug from the rod form a gradually-deepening V-shaped peripheral groove in the rod, the .sides of which ultimately constitute conical ends 240, so that each slug after the first one severed from the rod has two tapering ends or heads, which are preferably slightly convex from base to apex. form approximately to the die-cavities, as shown by Fig. 6, so that the amount of metal displaced by the dies in pressing the slug to an approximately spherical form is much less than would be the case if the ends or heads of the blank were substantially fiat. In other words, the end portions of the blank are given an approximately hemispherical form by the cutters before the pressing operation, and the work devolving upon the dies is therefore correspondingly reduced. The displacement of the metal by the cutters results in the formation of bars or flanges at the bases of the conical heads, these flanges being of greater diameter than the intermediate body of the slug, so that the upper flange overhangs the jaws 59 and prevents the slug from slipping downwardly between the jaws. When the pressing-dies close upon the slug. they act first upon the pointed ends of the conical heads and convert said heads into two end zones w w, separated by the unformed central portion of the blank, as shown by Fig. 7. Thereafter the continued pressure of the dies upon the blank forms the intermediate zone These heads con- I ;1 of the sphere by reducing the distance between the end zones, and thus decreasing the length and increasing the diameter of the intermediate portion of the blank. The slug is thus given a spherical form by first conforming the conical ends to the die-cavities, an operation that requires only a minimum expenditure of power and displacement of metal, owing to the conical form of the said ends, and then conforming the central portion of the slug to the portions of the cliecavities not occupied by the end zones, thus forming the central zone. .I find that the formation of the central zone involves less displacement of metal in the form of a fin at the equator of the central zone than would be the case if the ends of the blank were flat, in which case the end zones and the central zone would be formed simultaneously and more metal would be displaced outwardly at the equator of the central zone in the form of a fin. The amount of metal that has to be removed by grinding is therefore reduced to the minimum;

I claim- That improvement in the method of making balls which consists in forming a slug having tapering ends or heads, the tip of the tapered ends or heads being substantially in line with the longitudinal center of the slug, then subjecting the slug to endwise-lorging pressure between concave dies to convert said heads into approximately hemispherical end zones and convert the intermediate portion of the slug into a central or equatorial zone, the said end and central zones constituting a substantially spherical body.

In testimony whereof I have afiixed my signature in presence of two witnesses.

MARGELLUS REID. 

